March 18, 2022

The agricultural pollution of Europe's groundwater

topic:	Sustainable Agriculture
located:	Spain, France, Croatia, Slovakia
editor:	Abby Klinkenberg

Editor’s Note: This article is part of our groundwater campaign, in observance of the UN Water Day. Find more groundwater-related articles here. 

While agricultural practices may only constitute 1.3 percent of the European Union’s GDP, they have a disproportionately negative impact on the potability of European groundwater. A September 2021 study published by the European Environment Agency found that “in the EU, agriculture is the main cause of groundwater's failure to achieve good chemical status, [due to] diffuse pollution from nitrates and pesticides.” In the agricultural industry, nitrates (found in fertilisers) and pesticides complement one another: the former bolsters internal nitrogen-based processes critical for plant growth while the latter eliminates external threats to the plant in question. Appropriate quantities of nitrates and eco-friendly biopesticides can allow crops to flourish without environmental repercussions; unfortunately, excessive use of fertilisers and reliance on damaging chemical pesticides across the continent are quite literally poisoning European wells.

As is the case in many walks of life, too much of a good thing can wreak havoc: the case of nitrates is no exception to this rule. In the Spanish region of Castilla y Léon, high rates of nitrates in drinking water have been directly linked to industrial pig farming (the region ranks in the top 20 in the EU in terms of its porcine population). Nitrates from pig manure, which is used as a fertiliser in nearby fields, leak into the groundwater used by local communities. While this practice is tolerable in moderation, “the real problem is its scale.” As farmers strive to provide the globalised world with coveted Spanish pork products, the environment is paying the price: “In some of Spain’s main pig farming regions groundwater nitrate levels have been found to be up to four times higher than the legal threshold of 50 miligrams per litre. While this is not so common, lower illegal levels are widespread.” High levels of nitrate are associated with various health risks, including miscarriage, birth defects, and cancers. According to Greenpeace, 23 percent of Spanish groundwater suffers from nitrate contamination; Spain is facing litigation in the European Court of Justice for its ongoing failure to address the issue.

However, this problem extends beyond Spain’s agricultural regions: an October 2021 report on nitrates published by the European Commission stated that between 2016 and 2019, “14.1 percent of [EU] groundwater stations still exceed” the legal limit. The report revises Greenpeace’s slightly lower estimate, asserting that 20 percent of Spain’s groundwater monitoring stations suffer from illegal concentrations of nitrate; this figure only ranks third in the EU - “a high percentage of groundwater monitoring stations still show levels that are above the maximum… in Malta, Germany, Luxembourg, Spain, Portugal and Belgium (Flanders region).” The case in Malta is particularly dire in that 66 percent of groundwater stations suffer from nitrate toxicity; “it is also estimated that 90 percent of the groundwater being extracted does not meet the European Union’s standards for safe drinking water due to high nitrate levels.”

While some agricultural practices like pig farming incentivise intensive nitrate usage, others rely more heavily on chemical pesticides to ensure bolstered production. Slovakia is at the centre of European discourse around groundwater contamination by pesticide pollutants: a December 2021 study published by the European Environment Agency states that a whopping 39 percent of Slovakia’s 215 reporting groundwater sites exceeded the legal pesticide threshold of 0.1 milligram per litre. This proportion is nearly twice the second highest toxicity rate among EU countries, which was registered in France with 20 percent of 1,791 reporting groundwater sites failing to meet legal pesticide standards. 

The herbicide atrazine seems to be the main culprit, not only in Slovakia but also across the EU: “exceedances of one or more pesticides were detected at between 3 percent and 7 percent of groundwater monitoring sites [across the bloc], mainly by atrazine and its metabolites.” The use of atrazine, which has been linked to endocrine disruption in humans, has been banned in the EU since 2004, but it has proven to be an incredibly resilient chemical, still affecting water tables to this day. In December 2017, high levels of atrazine were detected in Slovakia’s Zitny Ostrov protected water zone, the “largest reservoir of groundwater in central Europe.” While investigations into the behaviour of nearby agricultural cooperatives, which constitute approximately 78 percent of the Zitny Ostrov area, came under official scrutiny, as of 2020, “groundwater quality monitoring… revealed above-limit concentrations in the case of several indicators.” The state has not managed to address its issue of groundwater contamination despite the fact that “underground sources make up 80 percent of drinking water supplies in Slovakia.” 

As part of the EU, Slovakia has a responsibility to bring all of its groundwater sites into good chemical standing by 2027 at the latest.The European Commission also has reiterated its commitment to reducing the use of pesticides across the bloc by 50 percent by 2030, as outlined in the European Green Deal.

Photo by Scott Goodwill

Call to Action

Clean water: a drop of life

Support now